NSFW Video Shows Greenland Shark's Heart Beating Outside Its Body

A video posted to Twitter shows the massive heart of a Greenland shark beating – outside the animal’s body.

According to James Ducker, a PhD candidate who posted the footage, the still-pulsating heart was removed from the shark and kept beating using a system of pumps seen in the video. While researchers are unable to tell the shark’s age from the heart alone, Ducker told IFLScience an expedition log suggests it could have belonged to a mature female around 200 years old.  

"This video was made while investigating the cardiac system of the Greenland shark. They found many new facts and processes that [weren't] known previously as they tried to unlock how these sharks live longer than 400 years old," said Ducker, who was not involved in the study.

Greenland sharks (Somniosus microcephalus) have only recently come into the scientific limelight, but have inspired questions about vertebrate lifespans – and the quest for longevity – ever since. 

Living at depths of up to 2,200 meters (7,200 feet) in temperatures just above freezing, these dinosaur-esque underwater giants could be older than the United States of America. Little is known about the carnivorous scavengers, but initial estimates suggest the dogfish live for more than 272 years, and possibly even over 400. They are the longest-lived known species of invertebrate, beating out the 211-year-old bowhead whale by more than a century. Working out how their enormous hearts work could help researchers better understand the aging process, including age-related conditions like heart disease and cancer. Observations published last year record the shark’s incredibly slow heartbeat – just one beat every 10 seconds – that appears to have been sped up in the posted video.

 A 2016 study aged 28 female Greenland sharks taken by research vessels as accidental bycatch between 2010 and 2013 using radiocarbon dating techniques on the lenses of the shark’s eyes. Researchers believe the cold waters could help lengthen the animal’s lives by slowing down their growth, lowering their metabolic rate, and possibly activating anti-aging genes.

IFLScience spoke to David Ebert, Director of the Pacific Shark Research Center in California, who said there are some problems with the assumptions that the largest sharks are the oldest.

"Sharks are not bony fishes and have a reproductive and physiological mode that is closer to mammals than bony fishes," said Ebert. "So, smaller sharks may be older than the larger sharks. The modeling in the study using the largest sharks as the oldest throws off the age estimates. In effect, the 400-year-old shark could just as easily be 60 years old."

You can watch researchers with The Physiological Society release a Greenland shark carrying a pop-up satellite archival tag (PSAT), which helps scientists to track the shark's movements and learn from its migratory habits, below.